1. Field of the Invention
The present invention relates to a stator of an electric rotating machine, and an electric rotating machine having the stator.
2. Description of Related Art
In recent years, there is a growing need of electric rotating machines usable as electric motors or generators which are compact in size and of high quality.
For example, an electric rotating machine mounted on a vehicle is required to generate more output power because of increase of vehicle loads, although the space assigned to mount the electric rotating machine in an engine compartment is becoming smaller.
To meet the requirement, it is necessary to reduce the resistance of the phase windings of an electric rotating machine, increase the lamination factor of the electric conductors accommodated in the magnetic circuit of the stator of the electric rotating machine, and properly align and densify the turn portions of the phase windings.
There has been developed an electric rotating machine satisfying the above requirement which includes a stator having a stator core formed with slots along the circumferential direction thereof, a stator winding constituted by conductive wires wound on the slots, the stator winding including in-slot portions accommodated in the slots and turn portions each of which connects each adjacent two of the in-slot portions to each other. In this electric rotating machine, each turn portion is formed with a step portion extending in the direction parallel to the axial ends of the stator core, in order to increase the arranging density of the turn portions and to reduce the projection height of the turn portions from the stator core.
However, the electric rotating machine having such a structure has a problem in that a coolant such as ATF for cooling the stator does not sufficiently penetrate into the turn portions, causing the stator winding to be insufficiently cooled.